Water Softener Units
Any water supply that has a high mineral content, may be classed as hard water. The most common minerals that cause hard water are calcium and magnesium. These minerals are picked up by water, as it passes through (typically) limestone rocks, on its way down into the water table.
Boiler feed water
Industrial/domestic hot water systems
Pure water pre-treatment (e.g. reverse osmosis food industry)
Window/car cleaning company
Symptoms of Hard Water
Whilst not necessarily harmful to health, hard water can cause annoying or even destructive results in a household supply.
- Furring of taps and shower heads
- Furring up of kettles and boilers, reducing their efficiency
- Reduced lathering of soap and detergents
- Causing dry and itchy skin
- Unsightly marks on sinks, dishes and glassware
- Reduced pipe diameters, reducing water flow
How does it work?
A typical domestic softener system has two components: –
- A tall vessel (looks like a diver’s tank, but bigger) filled with special resin beads, which the water passes through
- A brine tank containing salt tablets for regeneration of the resins
The tall vessel is fitted with an automatic valve. The function of this valve is to allow treated water to pass through, to hold the flow whilst regeneration is performed and to draw up a brine solution.
Water passes through the vessel via the valve, it then percolates down through the resin bed. When the water passes through the resin bed, the positively charged ions of calcium and magnesium become attached to the resin, so the water leaves these ions Reduced. Periodically normally once every two weeks the hardness needs to be flushed away and the resin regenerated with a brine solution. The brine solution comes from the salt tank that comes with the softener, the control valve puts the fresh water in and draws the brine solution out for you. The only thing you have to do is make sure you keep the salt tank topped up with salt tablets, normally once every month. It is worthwhile lifting the lid on the salt tank and checking the salt is above the water level.
The process is an exchange, calcium and magnesium ions exchanged for sodium ions. It is important that you know the raw sodium content of your water before installing a water softener, so you can calculate the sodium ions added after softening, ensuring your water is soft and safe to drink. It is a misconception that softened water tastes salty because of the increase in Sodium.
When using softened water for drinking, we must always be aware of the level of sodium in the raw water supply. The process of ionic exchange will increase the level of sodium in the treated supply. Currently the maximum limit for sodium in drinking water is 200 milligrams/litre.